Re: Mesozoic-ware

[pharrinj@PLU.edu]

On Sat, 13 Jan 1996, Jeff Poling wrote:

> At 02:45 AM 1/13/96 -0500, Nicholas R. Longrich wrote:

> >Birds are dinosaurs, so does the commutative property (A=B, B=C, so
> >A=C) apply here and make them reptiles?
> 
>    Under cladistics, absolutely.
> 
> >I suppose we could argue they're 
> >sufficiently different from dinosaurs to qualify for their own class, but 
> >we still consider bats mammals, too, and dinosaurs have some significant 
> >differences of their own.  
> 
>    George O. clearly gives birds a new class.  Bob Bakker (who is by no
> means the only one, I just can't remember all the authors, I've read so many
> books) certainly would put them inside the Dinosauria as a sub-order or
> something.
> 

I generally like a compromise between strict cladistics and traditional 
systematics, but I'm going to have to go with the cladists on this one.  
Not only are birds dinosaurs, but they are also:

eudinosaurs (in my system, anything above _Lagosuchus_),
sarcodinosaurs (_Eoraptor_ + herrerasaurs + theropods),
theropods,
tetanurans,
neotetanurans (after Sereno; tetanurans minus megalosaurs),
coelurosaurs,
maniraptorans,
and arctometatarsalians.

Hence, they are deeply and inextricably nested within the Dinosauria.

I have no qualms about calling birds sauropsids; I just don't like 
calling them reptiles.

     Nick Pharris
     Pacific Lutheran University